The BS is located at \([0,0,40]^\top \) , and four VAs are located at \([200,0,40]^\top ,\)  \([0,200,40]^\top ,\)  \([0,200,40]^\top ,\)  \([0,-200,40]^\top \) , with unit \(\text{m}\) .
Four SPs are located at \([65,65,z_\mathrm {SP}]^\top ,\)  \([-65,65,z_\mathrm {SP}]^\top ,\)  \([-65,-65,z_\mathrm {SP}]^\top ,\)  \([65,-65,z_\mathrm {SP}]^\top \) , with unit \(\text{m}\)  and \(z_\text{SP} \sim \mathcal {U}(0,40).\) 
We set the detection probability \(p_\text{D} = 0.9 \)  within the field of view (FoV), the SP FoV is 50 m and VAs are always visible. We consider clutter intensity \(c(\mathbf {z})\)  follows Poisson distribution as \( \lambda /(4R_\text{max}\pi ^4)\)  as the average of the number of clutter measurements \(\lambda =1 \) , and the maximum sensing range \(R_\text{max} = 200\)  m. We use the average of the generalized optimal subpattern assignment (GOSPA) distance [1]} for measuring the mapping performance, and the parameter settings as [2]} for calculating GOSPA distance was used. Simulation results were obtained by averaging over 500 Monte Carlo runs.
